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When the legendary Yuzo Koshiro announced he was working on a new shmup called Earthion for his beloved Mega Drive / Genesis back in 2023, the anticipation of fans all over the world was palpable.

Koshiro – famous for composing music for the likes of Streets of Rage, Revenge of Shinobi and Etrian Odyssey – is a seasoned shmup junkie, so the promise of a classic take on the genre combined with his exceptional audio talents was enough to propel Earthion to the top of many people's most wanted list.

Now, in 2025, Earthion is finally with us – and it shouldn't come as a tremendous shock to learn that it absolutely lives up to its potential, and is arguably one of the best shooters available on Sega's 16-bit system.

Sadly, because that version has been delayed, I'm not able to tell you exactly how it plays on the Mega Drive – but all of the other versions (including the Steam one I've covering here, which has launched ahead of the PlayStation, Xbox and Switch ports) are running the game under emulation, so what you experience on modern systems should be pretty much one-for-one when compared to the cartridge-based 16-bit edition, which launches next year.

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One of the reasons it succeeds is that Earthion keeps things relatively simple in terms of gameplay. Your ship has two main offensive options: your standard shot and sub-weapons, which are collected during each level. You can hold two sub-weapons (at least initially) and are able to toggle between them at will; these range from powerful missiles to lock-on lasers and eight-way shots, and they're usually distributed at points in each stage where they are of the most use.

It's possible to fire your main and sub-weapons independently, or fire them both at the same time. The reason for this is that if you get hit while using your sub-weapon, you lose it – so there are times when you'll want to stick with the main shot type (say, when taking down grunt enemies) to avoid being placed in a situation where you don't have a sub-weapon and are considerably weaker. It's just one example of how nuanced the gameplay mechanics are in this game.

You're able to power up both weapon types by collecting green Solrium gems, dropped by fallen enemies. Your craft can take multiple hits thanks to its shield system, and – should you avoid being hit a second time – these will recharge. When combined with the traditional stock of lives, this creates what feels like a quite forgiving experience, at least in the initial stages.

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By keeping the mechanics relatively straightforward, Koshiro and Makoto Wada (the largely unsung director, planner and developer behind the game) have been able to focus their attention on crafting a truly sublime shmup experience.

Earthion's eight levels are diverse and appealing, even after you've flown through them multiple times; the opening stage takes place during a massive space battle between rival fleets, tasking the player with taking down waves of foes as well as avoiding debris from exploding space cruisers. There's a mid-boss and end-of-level boss in each stage, and while some are more impressive than others visually, they all represent a decent level of challenge.

Later levels feature the usual organic, earth and space station tropes, but they're all presented in a way which makes them look and feel fresh – a testament to Wada's amazing artistic ability, honed on titles like Gotta Protectors: Cart Of Darkness and Royal Anapoko Academy. As we all know, the Genesis / Mega Drive can't do sprite scaling, but Wada imitates the effect in clever ways that really need to be seen to be believed. To say this is one of the best-looking Genesis / Mega Drive games would be a grave understatement; it's a visual treat in every regard.

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It's also one of the best-sounding games, but then again, that was never really in doubt. Koshiro is the undisputed master of the Mega Drive audio hardware, and in Earthion, he has composed what could well stand as his magnum opus on 16-bit hardware, even if it's slightly different in tone when compared to the techno-style soundtracks he became famous for with the Streets of Rage series.

It feels to me like Earthion's tunes are inspired by the classic shooter series of yesteryear, such as Gradius, Darius and Thunder Force, and with peppy, inspirational songs mixed in with tracks that hint at intergalactic malevolence.

Some of the tunes are so rich in structure you'd swear they were running on more powerful hardware, yet each song retains that classic Mega Drive signature FM sound, right down to the iconic drum beats and scratchy voice samples. There are moments of welcome humour thrown into the audio mix, too, such as a mid-boss who flies on-screen accompanied by R2-D2's famous beeps-and-boops.

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Shmup junkies know that this kind of game lives or dies on its challenge; make it too easy, and you'll breeze through in a single sitting (a common problem with many Genesis / Mega Drive shooters back in the '90s). However, if you head in the opposite direction and make things too taxing, you risk alienating a wider audience.

The solution Koshiro and Wada have concocted solves this issue; very much like genre legend Radiant Silvergun, Earthion allows you to retain your progress between play sessions, carrying over lives, power levels and expansion slots via an old-school password system (a save system would have been preferable, but I'll let it slide).

At this point, it's worth explaining how this expansion system works. If you finish a level with an 'Adapation Pod' as one of your sub-weapons, you'll get the option to permanently enhance one aspect of your ship.

This could be boosting the maximum power level of your weapons (10 being the maximum), adding in another weapon power / shield slot or altering the balance of your slots so you can retain more sub-weapons, but at the expense of a power / shield slot. You can also choose to start the next stage with a new sub-weapon or add an extra life to your stock, if you wish.

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This system means that newcomers can ease themselves into Earthion's challenge gently, starting the game on 'Easy' mode and using the Adaptation Pods to augment the power of their ship before tackling the game's default 'Normal' difficulty setting. Once you're comfortable on 'Normal' (and finishing the game on this setting is no mean feat), you can move on to the 'Hard' and 'Hotshot' modes, which ramp up the challenge massively.

What makes this approach so appealing is that it's entirely optional; if you're a shump veteran, you can ignore the upgrade path offered by the Adaptation Pods, just as you can choose to ignore the ability to continue using credits when you run out of lives. Whichever direction you approach the game from, there's plenty of longevity here, more so than your typical 16-bit shmup – as well as special Caravan-style 'Challenge' levels which offer unique stage setups and expect you to obtain the best score possible in the time given.

Still, Earthion does eventually come to an end; even the most novice of players will reach the conclusion in the space of a few days on 'Easy' mode, so your long-term enjoyment is going to be determined by how much you fancy digging back into the game's levels, and how much the music and overall retro vibe chime with you personally. The inclusion of an online leaderboard also helps extend the game's lifespan (for obvious reasons, this won't be included in the 16-bit edition).

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While this is effectively the Mega Drive ROM running on modern hardware, there are some extra treats included if you're playing on Steam or a console. You can tinker around with a selection of filters to truly nail that 'retro' look (although I have to admit I turned all of the filters off so I could properly appreciate the stunning pixel artwork), as well as alter various audio settings.

It's even possible to play some of the early demo versions of the game, which are fascinating from a historical perspective; they show how Earthion has evolved in subtle ways over the past few years.

Conclusion

Earthion is everything I'd hoped it would be when Yuzo Koshiro first announced it; a challenging shmup which pushes Sega's 16-bit hardware to its limits in terms of visuals and audio whilst combining a high level of polish with tight gameplay and plenty of longevity.

On a system that has more than its fair share of quality shooters, Earthion stands out as one of the best – and while purists have to wait a little longer to play the 'real' version of the game on the Mega Drive / Genesis, this emulated edition is perhaps the ideal way to experience it thanks to creature comforts such as screen filters and granular control over audio and visual settings, plus the addition of things like online leaderboards and prototype builds of the game.

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There will be some who might grumble at how old-school Earthion is when compared to modern shmups, but those complaints miss the point; Koshiro and collaborator Makoto Wada sought to create the best possible shooter for the Genesis / Mega Drive, bound by the technical constraints of hardware that is now over 30 years old. They have achieved that goal in spectacular fashion, making this a must-have for fans of the genre and those who appreciate retro gaming in general.